The crash happens when trying to regulate audio gain of a clip placed on a stereo audio track. If I change this stereoclip into 2 monos( using 2 tracks on the timeline),the audio gain corrections work normaly.

Not necessarily. Try launching Pr while holding down the Alt+Shift keys. Keep holding them down until the Welcome screen appears. The Alt key resets your preferences, and the Shift key clears the plug-in cache.